Effects of autotomy and regeneration on detection and capture of prey in a generalist predator

Many vertebrate and invertebrate taxa have the ability to autotomize and later regenerate appendages and with this process come both costs and benefits. For example, an animal might lose a leg to avoid a predator but as a result become a less effective predator itself. These impacts of autotomy and regeneration on foraging might differ based on habitat complexity as well. We used spiders as a model system to address this. We tested the effects of autotomy and regeneration on prey capture in juvenile Schizocosa ocreata wolf spiders in both artificial and seminatural settings. We tested spiders for prey capture efficiency in a laboratory arena with cricket prey. We also investigated sensory detection of prey through vibration by placing spiders in the same type of arena but visually isolating them from their prey. Subsequent analyses showed no effects of autotomy or regeneration on any measures of prey capture efficiency. Similarly, spiders' vibratory sensory abilities were not significantly affected by autotomy or regeneration. However, we found that when spiders were tested in a seminatural habitat (a leaf litter--filled mesocosm), individuals with a missing or regenerating leg had reduced prey capture rates. This suggests that the negative effects of autotomy and regeneration on foraging might be higher for predators in more complex environments. Copyright 2008, Oxford University Press.